Alignment of EUV and X-ray optics, from the simplest to the most complex systems
The best optic cannot deliver its promise if not perfectly aligned. Due to the very short wavelength, the required alignment accuracy increases dramatically as compared to visible light, imposing the use of at-wavelength wavefront sensors.
The shorter the wavelengths, the most accurate the metrology has to be. This postulate is well-known from optic manufacturers and optics designers. For more than a decade, Imagine Optic’s EUV and hard X-ray sensors demonstrated to be indispensable tool for single optic alignment, such as an off-axis parabola and a toroidal mirror, to benders and active optics under grazing and normal incidences. In order to better answer client needs, we have developped an EUV Wavefront sensor enabling to measure beam with numerical aperture higher than 0.1. This is sensor is placed under vacuum (compatible 1E-6 mbar) to catch very divergent beams.
“Automatic alignment of a Kirkpatrick–Baez active optic by use of a soft-x-ray Hartmann wavefront sensor” P. Mercère, M. Idir, T. Moreno, G. Cauchon, G. Dovillaire, X. Levecq, L. Couvel, S. Bucourt and P. Zeitoun, Optics Letter 31, 199 (2006)
“Wavefront observation at FLASH” M. Kuhlmann, E. Plönjes, K. Tiedtke, S. Toleikis,P. Zeitoun, J. Gautier, T. Lefrou, D. Douillet, P. Mercère, G. Dovillaire, X. Levecq, S. Bucour, and M. Fajardo, Proceedings of FEL2006, BESSY, Berlin, Germany, 794 (2006)
“Hartmann wave-front measurement at 13.4 nm with lEUV/120 accuracy” P. Mercère, P. Zeitoun, M. Idir, S. Le Pape, D. Douillet, X. Levecq, G. Dovillaire, S. Bucourt, K. A. Goldberg, P. P. Naulleau, and S. Rekawa, Optics Letters 28, 1534 (2003)